[LTP] [PATCH] Hugetlb: Migrating libhugetlbfs test truncate_reserve_wraparound.c

[Geetika]

Test Description:
Test to verify the Hugepages_Rsvd before and after mmap, truncate and sigbus operations.
At one stage, improper handling of tests against i_size could mess
up accounting of reserved hugepages on certain truncate operations.

Signed-off-by: Geetika <geetika@linux.ibm.com>
---
 runtest/hugetlb                               |   1 +
 testcases/kernel/mem/.gitignore               |   1 +
 .../kernel/mem/hugetlb/hugemmap/hugemmap38.c  | 124 ++++++++++++++++++
 3 files changed, 126 insertions(+)
 create mode 100644 testcases/kernel/mem/hugetlb/hugemmap/hugemmap38.c

diff --git a/runtest/hugetlb b/runtest/hugetlb
index 299c07ac9..2ffd35aec 100644
--- a/runtest/hugetlb
+++ b/runtest/hugetlb
@@ -35,6 +35,7 @@ hugemmap29 hugemmap29
 hugemmap30 hugemmap30
 hugemmap31 hugemmap31
 hugemmap32 hugemmap32
+hugemmap38 hugemmap38
 hugemmap05_1 hugemmap05 -m
 hugemmap05_2 hugemmap05 -s
 hugemmap05_3 hugemmap05 -s -m
diff --git a/testcases/kernel/mem/.gitignore b/testcases/kernel/mem/.gitignore
index 7258489ed..346bf9533 100644
--- a/testcases/kernel/mem/.gitignore
+++ b/testcases/kernel/mem/.gitignore
@@ -34,6 +34,7 @@
 /hugetlb/hugemmap/hugemmap30
 /hugetlb/hugemmap/hugemmap31
 /hugetlb/hugemmap/hugemmap32
+/hugetlb/hugemmap/hugemmap38
 /hugetlb/hugeshmat/hugeshmat01
 /hugetlb/hugeshmat/hugeshmat02
 /hugetlb/hugeshmat/hugeshmat03
diff --git a/testcases/kernel/mem/hugetlb/hugemmap/hugemmap38.c b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap38.c
new file mode 100644
index 000000000..2de6aa4da
--- /dev/null
+++ b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap38.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ * Copyright (C) 2005-2006 David Gibson & Adam Litke, IBM Corporation.
+ * Copyright (C) 2006 Hugh Dickins <hugh@veritas.com>
+ */
+
+/*\
+ *[Descripiton]
+ *
+ * At one stage, improper handling of tests against i_size could mess
+ * up accounting of reserved hugepages on certain truncate
+ * operations.
+ *
+ */
+
+#include <signal.h>
+#include <setjmp.h>
+#include "hugetlb.h"
+
+#define MNTPOINT "hugetlbfs/"
+#define RANDOM_CONSTANT 0x1234ABCD
+
+static long hpage_size;
+static int fd = -1;
+static int sigbus_count;
+static unsigned long initial_rsvd, after_map_rsvd, after_touch_rsvd;
+static unsigned long after_trunc_rsvd, after_unmap_rsvd, after_sigbus_rsvd;
+static volatile unsigned int *q;
+
+
+static sigjmp_buf sig_escape;
+
+static void sigbus_handler(int signum, siginfo_t *si, void *uc)
+{
+	siglongjmp(sig_escape, 17);
+}
+
+static void run_test(void)
+{
+	void *p;
+	struct sigaction sa = {
+	.sa_sigaction = sigbus_handler,
+	.sa_flags = SA_SIGINFO,
+	};
+
+	sigbus_count = 0;
+
+	initial_rsvd = SAFE_READ_MEMINFO(MEMINFO_HPAGE_RSVD);
+	tst_res(TINFO, "Reserve count before map: %lu\n", initial_rsvd);
+
+	p = SAFE_MMAP(NULL, hpage_size, PROT_READ|PROT_WRITE, MAP_SHARED,
+			fd, 0);
+	q = p;
+
+	after_map_rsvd = SAFE_READ_MEMINFO(MEMINFO_HPAGE_RSVD);
+	tst_res(TINFO, "Reserve count after map: %lu\n", after_map_rsvd);
+
+	*q = 0;
+	after_touch_rsvd = SAFE_READ_MEMINFO(MEMINFO_HPAGE_RSVD);
+	tst_res(TINFO, "Reserve count after touch: %lu\n", after_touch_rsvd);
+
+	SAFE_FTRUNCATE(fd, 0);
+	after_trunc_rsvd = SAFE_READ_MEMINFO(MEMINFO_HPAGE_RSVD);
+	tst_res(TINFO, "Reserve count after truncate: %lu\n", after_trunc_rsvd);
+
+	if (after_trunc_rsvd != initial_rsvd) {
+		tst_res(TFAIL, "Reserved count is not restored after truncate: %lu instead of %lu", after_trunc_rsvd, initial_rsvd);
+		goto windup;
+	}
+
+	SAFE_SIGACTION(SIGBUS, &sa, NULL);
+	if (sigsetjmp(sig_escape, 1) == 0)
+		*q; /* Fault, triggering a SIGBUS */
+	else
+		sigbus_count++;
+
+	if (sigbus_count != 1) {
+		tst_res(TFAIL, "Didn't SIGBUS after truncate");
+		goto windup;
+	}
+
+	after_sigbus_rsvd = SAFE_READ_MEMINFO(MEMINFO_HPAGE_RSVD);
+	tst_res(TINFO, "Reserve count after truncate: %lu\n", after_sigbus_rsvd);
+
+	if (after_trunc_rsvd != initial_rsvd) {
+		tst_res(TFAIL, "Reserved count is altered by SIGBUS fault: %lu instead of %lu", after_sigbus_rsvd, initial_rsvd);
+		goto windup;
+	}
+
+	tst_res(TPASS, "Test passed!");
+
+windup:
+	SAFE_MUNMAP(p, hpage_size);
+	after_unmap_rsvd = SAFE_READ_MEMINFO(MEMINFO_HPAGE_RSVD);
+	tst_res(TINFO, "Reserve count after munmap: %lu\n", after_unmap_rsvd);
+
+}
+
+static void setup(void)
+{
+	hpage_size = tst_get_hugepage_size();
+	fd = tst_creat_unlinked(MNTPOINT, 0);
+}
+
+static void cleanup(void)
+{
+	if (fd >= 0)
+		SAFE_CLOSE(fd);
+}
+
+static struct tst_test test = {
+	.tags = (struct tst_tag[]) {
+		{"linux-git", "ebed4bfc8da8"},
+		{}
+	},
+	.needs_root = 1,
+	.mntpoint = MNTPOINT,
+	.needs_hugetlbfs = 1,
+	.hugepages = {4, TST_NEEDS},
+	.setup = setup,
+	.cleanup = cleanup,
+	.test_all = run_test,
+};
+
-- 
2.39.2 (Apple Git-143)